An embodiment of the present invention relates to a tool engaging head on a fastener having a plurality of extending portions thereon, such as fins or xe2x80x9cflashesxe2x80x9d, for indicating when someone has tampered with the fastener. Another embodiment of the present invention relates to a fastener that includes a tamper evident sleeve.
In many situations, fasteners must be applied to an assembly using a certain torque, thereby assuring that the fasteners are seated to the assembly under the proper tension. If this proper tension of the fasteners within the assembly is changed, the assembly may not be able to effectively perform its operation, thereby possibly causing the assembly to malfunction.
The primary way that the tension of an installed fastener would change within an assembly would be by unauthorized users loosening, tightening or removing the fastener with a tool that engages with a head of the fastener. Because any user can freely place a tool around the head of a fastener and loosen, tighten or remove and reinsert the fastener to the assembly, it cannot be guaranteed that the fastener has not been tampered with, thereby causing uncertainty as to whether the fastener will cause problems for the assembly, and essentially cause the assembly to malfunction.
A general object of an embodiment of the invention is to provide a fastener having a tool engaging drive head having at least one extending portion thereon to prevent a tool from at least properly engaging with the tool engaging surfaces of the drive head of the fastener.
Another object of an embodiment of the invention is to provide a fastener having a tool engaging drive head having at least one extending portion thereon whereby if a standard drive tool is attempted to be engaged on the drive head above the extending portion, the tool will tend to cam out or rotate relative to the drive head since it cannot properly engage the tool engaging drive head.
Another object of an embodiment of the invention is to provide a fastener having a tool engaging drive head having at least one extending portion thereon whereby the extending portions can be removed so that a tool can engage with the tool engaging drive head in order to remove, loosen or tighten the fastener.
Yet another object of an embodiment of the invention is to give authorized personnel an indication when a fastener within an assembly has been tampered with, thereby allowing the authorized personnel to replace the tampered fastener with a new fastener.
Another object of an embodiment of the invention is to deter unauthorized users from tampering with the fastener since the tampering of the fastener will become known to authorized users.
A further object of an embodiment of the invention is to provide a fastener which will be able to be installed into an assembly without interfering with the tamper evident features of the fastener.
Briefly, and in accordance with at least one of the foregoing, an embodiment of the invention provides a fastener having a tamper indicating tool engaging drive head.
The fastener has a shank including a threaded shank portion. The fastener also has a double-headed driving portion that is integrally formed with the shank. The double-headed portion includes an outer head for driving the fastener into a work piece or nut and an inner head for removing the fastener from an assembly. The inner head is joined to the outer head such that the inner head is positioned between the outer head and the shank. Extending portions, such as fins or flashes, extend from tool engaging surfaces of the inner head. In use, the fastener is driven into an assembly via a proper tool that engages with the outer head. The outer head shears off the fastener when the desired torque is achieved, leaving only the shank within the assembly and the inner head exposed. Due to the extending portions on the tool engaging surfaces of the inner head, the fastener cannot be moved unless the extending portions are first broken off or otherwise removed from the inner head, thereby allowing a tool to properly engage with the tool engaging surfaces of the inner head. Because the extending portions must be removed for the tool to engage the fastener within the assembly, it will be evident when the fastener has been tampered with, thereby indicating to the proper personnel that the fastener should be replaced with a new fastener.
Another embodiment of the present invention provides a fastener having a sleeve thereon, such as on its inner head. The fastener includes a shank and a double-headed driving portion that is integrally formed with the shank. The double-headed portion includes an outer head for driving the fastener into a work piece or nut and an inner head for removing the fastener from a work piece or nut. The inner head is joined to the outer head such that the inner head is positioned between the outer head and the shank. At least one extending portion, such as a plurality of fins or flashes, extend from the inner head. The sleeve is disposed on the inner head, under the extending portions. The extending portions are configured to prevent the sleeve from being removed from the inner head, once the fastener has been installed, without there resulting some indication that someone has removed or at least tried to remove the sleeve from the fastener. The sleeve itself is configured to indicate when a tool has been engaged with the sleeve (i.e., engaged with the inner head) for purposes of removing the fastener. Preferably, the sleeve is made of tamper evident material, such as collapsible plastic that may be round in shape for difficult gripping. In use, the fastener is driven into an assembly via a proper tool that engages with the outer head. The outer head shears off the fastener when the desired torque is achieved, leaving only the shank within the assembly and the inner head exposed. Due to the extending portions on the inner head, the sleeve cannot be removed from the inner head without there resulting some indication of its removal. Due to the sleeve being disposed on the inner head, the fastener cannot be driven or rotated by engaging a tool with the sleeve without there resulting some indication that the fastener has been driven or rotated. Specifically, the sleeve is configured such that marring or gouges are formed on the sleeve as a result of engagement by a tool. To this end, the sleeve may be formed of plastic, fiber, rubber or some other suitable material.